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www.mineralgallery.co.za Minerals F-J |
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Gold |
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Name
Gold
Chemistry
Au
Uses
Coins, jewellery and medicine.
Color-
Gold-yellow, yellow-white
Hardness
2.5-3
Specific gravity
19.28 when pure
Crystal system:
Cubic. Crystal form -octahedron, dodecahedron and hexahedron
Accompanied by:
Stibnite, arsenopyrite, chalcopyrite, pyrite and quartz
Fracture
Hackly
Luster
Metallic
Cleavage
Absent
Streak
Yellow,shining
Similar to:
Chalcopyrite, pyrite
The formation and occurrence of gold is usually in hydrothermal vains, associated with quartz and sulphide minerals, mainly pyrite.
Resistance to chemical action is the reason for concentrated and alluvial deposits in stream beds after the host rock have been disintegrated
South Africa is a major gold producing country.